Redbud (Cercis canadensis), also known as Eastern Redbud or Judas Tree, is abundant in the southern two-thirds of Ohio, with scattered distribution in the northern one-third of the state . It heralds the arrival of spring with its showy, lavendar-pink flowers that typically open in April, long before the foliage emerges.
Redbud is a native of the entire eastern half of the United States except for New England, but is not found in Canada, as its scientific name implies.
This ornamental tree is rapidly growing and usually multitrunked in the wild, having a vase shape with a rounded crown that reaches about 20 feet tall and 20 feet wide at maturity, when found in the open. However, since it is often located at the edge of woodlands, it commonly has a leaning growth habit, trying to grow into as much sunlight as possible.
As a member of the Bean Family, Redbud is also related to Honeylocust, Kentucky Coffeetree, Black Locust, and Wisteria, as well as other types of Redbuds. The Bean Family is also known as the Legume, Pea, or Pulse Family, and may go by the alternative scientific family name of Leguminosae. Many of this family's members are important vegetable crops as well as ornamental plants.
Planting Requirements - Redbud prefers deep, moist, organic, well-drained soils, but adapts to many less-than-favorable soils of either acidic or alkaline pH as long as they are not wet. It grows most rapidly and flowers most prolifically in full sun if adequate moisture is available during the heat of summer, but it is often found in partial sun to partial shade in nature. It can grow in zones 4 to 9, but occurs naturally in zones 5 to 9.
Potential Problems - Redbud grows rapidly and often lives about twenty years before it begins to decline or die, especially in urban situations where poorly drained, heavy clay soils predominate.
Trunk canker is a serious disease of Redbud and is evident as sunken depressions in the bark of large branches or trunks, which often begin to heal before the tree eventually dies. Verticillium wilt and root rot are two additional, serious pathogens that affect the roots often due to wet soils but become evident as entire branches rapidly die. Some pests such as scales may also cause problems, but the tree diseases cited above wreak havoc on Redbud and limit its lifespan.
Identifying Features - Redbud
The alternate, heart-shaped leaves of Redbud are easily to identify, and make this the only member of the Bean Family in the eastern United States with simple leaves (that is, not compound and composed of many leaflets, like Honeylocust).
Fall color is often green well into late autumn, but in some years chartreuse to yellow leaves occur before leaf drop.
The floral buds of Redbud are not red during their winter dormancy, but rather they are dark brown. However, they become deep lavendar-pink when the buds begin to swell in early spring, and mature to a lighter color as they open as flowers.
The clustered perfect flowers are found primarily on the outermost twigs, but also scattered on the inner branches and trunks as well.
The blossoms are appealing in part because the foliage has not yet emerged in early spring. Vegetative buds break later, and a terminal bud is absent, as in most Bean Family members.
By late spring, the green fruits of Redbud take on the pod shape that is characteristic of members of the Bean Family.
By winter, the clustered, flattened fruits are brown to beige and serve as an excellent identification feature. Each fruit contains several small dark brown to black seeds.
The twigs of Redbud are zig-zag and hold either small, vegetative buds near their tips, or rounded, knobby floral buds further back.
Floral buds can also be found on branches and trunks, which contain mature bark that is composed of flattened, brown-black ridges that have orange furrows in-between.
The Bean Family